Only send events to renderers that are listening to an event....

chrome/browser/renderer_host/render_process_host.h

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_RENDERER_HOST_RENDER_PROCESS_HOST_H_
 #define CHROME_BROWSER_RENDERER_HOST_RENDER_PROCESS_HOST_H_
 
 #include <set>
+#include <string>
 
 #include "base/id_map.h"
 #include "base/process.h"
 #include "base/scoped_ptr.h"
 #include "chrome/common/ipc_sync_channel.h"
 #include "chrome/common/transport_dib.h"
 
 class Profile;
 
 // Virtual interface that represents the browser side of the browser <->
@@ skipping 201 matching lines @@
 // Factory object for RenderProcessHosts. Using this factory allows tests to
 // swap out a different one to use a TestRenderProcessHost.
 class RenderProcessHostFactory {
  public:
   virtual ~RenderProcessHostFactory() {}
   virtual RenderProcessHost* CreateRenderProcessHost(
       Profile* profile) const = 0;
 };
 
 #endif  // CHROME_BROWSER_RENDERER_HOST_RENDER_PROCESS_HOST_H_